1. Technical Field
This invention relates to protective devices for gas hot water heaters and, more particularly, to a gas hot water heater safety shield which includes a length of plastic or vinyl sheeting which is mounted circumferentially surrounding the base of the gas hot water heater, the sheeting extending upwards from the floor or a base plate approximately three feet, the sheeting mounted on the floor or base plate by a mounting device in fluid-tight connection with the floor or base plate, the safety shield thus acting to prevent heavier-than-air vapors from contacting the pilot light of the gas hot water heater.
2. Description of the Prior Art
The standard gas hot water in a residence is usually mounted in the basement of the residence on a low (six inch) metal stand. Three pipes usually feed into the gas water heater, a gas flow pipe, water inflow pipe and hot water outflow pipe. These are fed in from the ceiling of the basement and extends downwards to be connected to the gas hot water heater.
Most gas hot water heaters further include a pilot light which is a continually burning small flame inside the hot water heater adjacent the main gas burners usually positioned at the bottom of the hot water heater. The purpose of the pilot light is to ignite the outflowing gas when the gas is turned on thus heating the water held within the gas hot water heater.
To heat the water within the tank of the gas hot water heater most efficiently, the pilot light and main gas burners are usually positioned underneath the water tank at the bottom of the gas hot water heater. This means that the pilot light is usually only six to twelve inches off of the ground surface on which the hot water heater is placed. Furthermore, because the pilot light requires oxygen to burn, ventilation holes must be provided surrounding the pilot light to allow air to enter the gas hot water heater. For efficiency purposes, these air vents are usually located at the bottom of the gas hot water heater adjacent the pilot light. The end result is that in basements and/or garages where a gas hot water heater is placed, there is a generally open flame (the pilot light) only six to twelve inches above the floor.
Basements and garages are also used to store many other objects. These can and often do include hazardous chemicals and flammable materials such as turpentine, gasoline and other such volatile chemicals. Obviously, the degree of caution with which such items are stored varies from person to person and household to household but there have been numerous instances where such chemicals were stored near the gas hot water heater in the basement.
If a child, pet or any person were to accidentally spill a container containing such hazardous chemicals a serious problem may arise as the location of the spill approaches the location of the gas hot water heater, as is shown in FIG. 6a. The danger does not arise from the liquid itself, but rather from the heavier-than-air vapors emitted by the volatile chemical as it pools on the floor. The flammable vapors can travel over the floor surface beyond the perimeter of the liquid spill, subject to the vagaries of the air currents in the basement or garage. It is important to note, however, that due to the heat radiating from the hot water heater, there is an upward flow of hot air from the area surrounding the hot water heater which results in cooler air being pulled in from underneath the rising column of warm air. Therefore, there is often a slight air flow towards the base of the gas hot water heater which, in normal circumstances, helps to provide air circulation thus insuring oxygen flow to the pilot light. In a situation where a spill of a volatile chemical has occurred in the area of the gas hot water heater, this inflow of air from the area surrounding the gas hot water heater will tend to draw the heavier-than-air vapors emitted by the volatile chemical towards to the gas hot water heater base. The danger thus becomes apparent, as the vapors can be sucked into the gas hot water heater through the air flow vents surrounding the pilot light. When the vapors contact the pilot light, the vapors may be ignited by the pilot light, the vapor acting as a type of "fuse" leading back to the original liquid chemical spill. In a matter of seconds the entire spill can be set afire, igniting all other combustible objects in the area and quickly engulfing the basement or garage in flames. There is therefore a need for a protective device to prevent heavier-than-air vapors such as those described above from contacting the pilot light of the gas hot water heater.
Some manufacturers of gas hot water heaters have attempted to solve the problem of heavier-than-air vapors by placing a warning sticker on the gas hot water heater itself and placing the gas hot water heater on a three foot high stand that can be installed under the water heater. While this solution may be marginally acceptable for new homes in which the hot water heater may be installed as a new unit, it is clear that such a solution is impractical as a retrofit kit for already installed gas hot water heaters. One can envision the ordeal involved in moving the hot water heater upwards two and one-half feet, including cutting, shortening and/or rerouting the pipe described previously, lifting the heavy hot water heater unit to the correct height, changing the height of the exhaust opening to correspond to the new height of the hot water heater and, finally, resetting the hot water heater on the new taller stand. Furthermore, the additional height of the gas water heater will render the heater more unstable as the center of gravity of the unit has been raised a greater distance above the floor. Therefore, the gas hot water heater may be more prone to tipping over in the event of earthquakes or the like. There is therefore a need for a safety device for gas hot water heaters which can be used with both new and already installed heater units.
Therefore, an object of the present invention is to provide an improved gas hot water heater safety device.
Another object of the present invention is to provide a gas hot water heater safety shield which includes a floor-mounted plastic or vinyl fluid-impervious sheet material extending circumferentially around the base of the gas hot water heater and extending upwards to a height of approximately three feet which will act to prevent heavier-than-air vapors from contacting the pilot light and possibly igniting.
Another object of the present invention is to provide a gas hot water heater safety shield which may be quickly and easily mounted to the surrounding floor adjacent the gas hot water heater by a plastic fluid-impervious sheet mounting strip which is mounted in fluid-tight relation to the floor itself.
Another object of the present invention is to provide a gas hot water heater safety shield which may be installed on a plate mounted to the underside of the hot water heater unit itself so that the gas hot water heater may be shipped from the factory with the safety shield already installed thereon.
Another object of the present invention is to provide a gas hot water heater safety shield which is constructed of relatively inexpensive materials to insure that the safety device may be afforded by all persons owning gas water heaters.
Another object of the present invention is to provide a gas hot water heater safety shield which may be mounted on the floor adjacent the gas hot water heater in a variety of different configurations to permit the shield to be used in the greatest number of environments and setups.
Finally, an object of the present invention is to provide a gas hot water heater safety shield which is relatively simple and inexpensive to manufacture and is safe and efficient to use.